1. Field of Endeavor
The present invention relates to computer input devices and more particularly to a wireless computer input system.
2. State of Technology
The abstract of U.S. Pat. No. 4,988,981 for a computer data entry and manipulation apparatus and method by Thomas G. Zimmerman and Jaron Z. Lanier, patented Jan. 29, 1991, provides the following description: xe2x80x9cApparatus is disclosed for generating control signals for the manipulation of virtual objects in a computer system according to the gestures and positions of an operator""s hand or other body part. The apparatus includes a glove worn on the hand which includes sensors for detecting the gestures of the hand, as well as hand position sensing means coupled to the glove and to the computer system for detecting the position of the hand with respect to the system. The computer system includes circuitry connected to receive the gesture signals and the hand position signals for generating control signals in response thereto. Typically, the control signals are used to manipulate a graphical representation of the operator""s hand which is displayed on a monitor coupled to the computer system, and the graphical representations of the operator""s hand manipulates virtual objects or tools also displayed by the computer.xe2x80x9d
The abstract of U.S. Pat. No. 5,414,256 for an apparatus for and method of controlling a device by sensing radiation having an emission space and a sensing space by Asaf Gurner and Oded Y. Zur, patented May 9, 1995 provides the following description, xe2x80x9cAn optical controller is capable of surrounding a player with a radiation screen from a plurality of panels, and enables the player to produce control signals for interface with a controlled instrument such as a musical instrument, a video game processor, etc. The insertion of the appendage of the player can produce a functional control signal. The relative position of the insertion of the appendage can be determined, for example, as a result of the intensity of the reflected radiation in the dispersing radiation screen and adjusted in elevation. The video game processing unit can play either a conventional video game that usually accepts eight functional control signals, or it can utilize the full capacities of the control signals available from the optical controller for enhanced play action.xe2x80x9d
The abstract of U.S. Pat. No. 5,442,168 for a dynamically-activated optical instrument for producing control signals having a self-calibration means by Asaf Gurner and Oded Y. Zur, patented Aug. 15, 1995 provides the following description, xe2x80x9cAn optical controller is capable of surrounding a player with a radiation screen from a plurality of panels, and enables the player to produce control signals for interface with a controlled instrument such as a musical instrument, a video game processor, etc. The insertion of the appendage of the player can produce a functional control signal. The relative position of the insertion of the appendage can be determined, for example, as a result of the intensity of reflected radiation in the dispersing radiation screen. The video game processing unit can play either a conventional video game that usually accepts eight functional control signals, or it can utilize the full capacities of the control signals available from the optical controller. The player can simulate the movements of the video character to experience a more realistic game play action.xe2x80x9d
U.S. Pat. No. 5,510,800 for a time-of-flight radio location system by Thomas E. McEwan, patented Apr. 23, 1996 and U.S. Pat. No. 5,661,490 for a time-of-flight radio location system by Thomas E. McEwan, patented Aug. 26, 1997 provide the following descriptions, xe2x80x9cA bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence.
FIG. 13 of McEwan Pat. No. 5,510,800 illustrates a simple head position sensing system implemented according to the present invention. In this system, a transmitter 500 is mounted on a user""s headset 501, worn by a user of a computer system 502. The receiver box 503 is mounted on the computer system 502 and connected across cable 504 to a standard mouse interface. The receiver box 503 includes a first receiver 505, a second receiver 506 and a third receiver 507 each generating a time-of-flight measurement for pulses generated by the transmitter 501. The receiver box 503 produces data indicating the time-of-flight from the transmitter 500 to each of the three receivers 505, 506, 507 can be used for precise position detection of the transmitter 500 mounted on the headset 501. The user is tethered by a small diameter coaxial cable 508 to the receiver box 503 to provide timing in the embodiments described. Computer system 502 includes the standard monitor 510 and keyboard 511 and may be used for executing interactive computer programming based on the position data produced according to the present invention. Various arrangements of the transmitters and receivers may be used to triangulate, providing six axis information: x, y, z in translation and 3 axes of rotation for the transmitter 500.xe2x80x9d
The abstract of U.S. Pat. No. 5,982,352 for a method for providing human input to a computer by Timothy R. Pryor, patented Nov. 9, 1999, provides the following description, xe2x80x9cThe invention provides a method for providing human input to a computer which allows a user to interact with a display connected to the computer. The method includes the steps of placing a first target on a first portion of the user""s body, using an electro-optical sensing means, sensing data related to the location of the first target and data related to the location of a second portion of the user""s body, the first and second portions of the user""s body being movable relative to each other, providing an output of the electro-optical sensing means to the input of the computer, determining the location of the first target and the location of the second portion of the user""s body, and varying the output of the computer to the display based upon the determined locations for contemporaneous viewing by the user.xe2x80x9d
The abstract of International Patent No. WO 99/25152A3 for xe2x80x9cINTERACTIVE DEVICES AND METHODS,xe2x80x9d published May 20, 1999 provides the following description, xe2x80x9cA body-wearable interactive device with a retractable earbud and a microphone provides data, audio and voice communication with a wearable personal computing or other remote device. Full voice and display interface with a personal computer can be achieved with the use of a wireless link between the input/output device and computer. The device is adapted for use with a variety of ancillary communications devices to provide flexibility in field and mobile communications scenarios. Corresponding methods are also disclosed by which a wearer can effect communication through and with the interactive device.xe2x80x9d
Discussion of Background Artxe2x80x94There is a wide variety of literature on devices that enable a human user to input information into a computer system by moving or manipulating a hand-held object or moving or manipulating an object attached to a user""s body. For purposes of explaining the present invention, such devices are part of a class of objects called xe2x80x9ccomputer input devices,xe2x80x9d which will be also called xe2x80x9cinput devicesxe2x80x9d or xe2x80x9clocator-unitsxe2x80x9d in this application. The most common computer input device (excepting the typing keyboard) is the ubiquitous computer xe2x80x9cmouse.xe2x80x9d
Many other methods and systems have been described that enable input devices to provide information to a digital computer for purposes of moving a cursor on a monitor screen, for xe2x80x9cclickingxe2x80x9d on a menu object, and for many other applications. Many combinations of mechanical, optical, electronic, and acoustic devices have been investigated for rendering hand motion into an electronic signal that represents the hand motion. These systems then convey such motion information to a digital computer input system, where the electronic signal is processed into computer control information. This control information is usually displayed on a computer monitor screen for purposes of graphical communication to the user, and for user direction to the computer and attached systems. Examples include the presentation of a screen xe2x80x9ccursorxe2x80x9d that moves proportionally to the hand motion. If the cursor is moved to a screen menu, its presence can cause a xe2x80x9cmenuxe2x80x9d of options to be displayed, and when a hand activated button is pressed, said menu item is xe2x80x9cselectedxe2x80x9d meaning that the computer is directed (i.e., controlled) to do something associated with the menu symbol.
For purposes of explaining the present invention, motion detection or motion measurement is defined here to mean automated distance measuring over a time interval usually associated with hand movement of an object; or it can mean the distance traveled of a locator unit from the xe2x80x9con-clickxe2x80x9d of a device button and lasting until the xe2x80x9coff-clickxe2x80x9d or release of a device button. This definition of motion is one of xe2x80x9crelative motionxe2x80x9d from a start-of-measurement signal to an end signal, or from xe2x80x9cstartxe2x80x9d to a next start-of-measurement signal.
An example of relative-motion measurement is illustrated by the hand-moved xe2x80x9cmouse.xe2x80x9d This device relates rolling motion of an element, which is caused to roll by friction contact against a surface, to linear motion of a cursor on a computer screen. In other words, the distance moved by the periphery of the ball""s surface, is measured using a combination of electrical, mechanical, or optical elements; and this distance is scaled, using software, to cause a cursor on a computer monitor screen to move a desired distance on a screen. Such devices usually work by providing two degrees of motion information in two orthogonal dimensions (e.g., x and y) by rolling on a surface. One commonly used variation of this device is to use a stationary supported rolling element that points upwards, and which is xe2x80x9crolledxe2x80x9d by the palm of a user""s hand as it rolls over the surface of the ball. The direction and distance of hand motion is converted to x and y coordinate changes, which are converted to up/down and sideways motion on a monitor screen.
Many system variations have been described that are intended to enable the hand-directed motion of the xe2x80x9cmousexe2x80x9d to be more easily rendered for purposes of being more cheaply constructed, safer to use, more accurate, and many other reasons. These variations have employed low-power electromagnetic ranging radars, ranging acoustic systems, optical imaging systems to convert image motion to distance, gloves with light emitters coupled with optical triangulation systems for distance measurement, intelligent pads upon which the mouse moves and the pad senses the mouse""s location, and many others. These other types of systems have not been widely accepted by users because of cost, reliability, interference with other objects, needed workspace requirements, FCC and FDA licensing issues, safety issues, encumbering issues to the user""s hands, and other problems.
Devices employing light emitting elements, such as optical fiber or LEDs (light emitting diodes), use optical sensors to determine the distance traveled of one or more light emitters. An optical sensor, such as CCD camera, can view the light spots from several directions. Then the relative motion of an emitting source can be measured and scaled, using triangulation techniques, using computer software, to direct a cursor or some other element on a computer screen, to move in proportion to the light emitter motions.
Computer input devices using low-power radar or ultra-sonic systems (with transmitters located either in the hand-held input device or at the edges of the workspace), usually measure either absolute distances (i.e., range) from a start location to an end location, or they measure frequency shifts associated with velocity which must be integrated to obtain distance traveled. The distance traveled is defined by subtracting the initial-location coordinates from the final-location coordinates. These radar and acoustic devices suffer from lack of resolution, especially at the required millimeter distance or at the sub-millimeter/second velocity resolution levels of a hand-directed unit. They are expensive, use too much power to be wireless, often have safety issues, are incompatible with FCC radio-emission issues, suffer from multi-path and from xe2x80x9cclutterxe2x80x9d effects, and commonly require wired attachment to the hand- or body-directed system component.
Other existing hand-held computer input devices such as the xe2x80x9cmousexe2x80x9d with rolling elements, or gloves with optical emitters, all suffer from one or more other problems. These include requiring wired connections, requiring clear lines-of-sight from the device to a camera, or it must rest on a table surface, or it lacks needed accuracy, or they are only useable by one person at a time. In addition, rolling devices are sensitive to being disabled by dirt; and gloves with attached wires impede the motions of the user. An important issue is that the xe2x80x9cmousexe2x80x9d and the xe2x80x9cclickxe2x80x9d buttons cause repetitive motion injury to many users. These injuries appear to occur because the mouse-motion on a plane and the location of the attached buttons is incompatible with natural hand-wrist-finger motions.
In response to the concerns discussed in the prior art, what is needed is a system and method for a low-cost relative distance determining input device that overcomes the problems of the prior art. The present invention provides systems and methods to improve relative-distance input devices employing low-cost, wireless input devices for computers and other automated systems.
The present invention provides an electromagnetic (i.e., EM) system for controlling a computer display in a workspace using an input unit/output unit. A train of low power EM waves are sent out to flood the workspace. EM waves are reflected from the input unit/output unit and measured. A relative distance moved information signal is created using the EM waves that are reflected from the input unit/output unit and measured. Algorithms are used to convert the relative distance moved information signal to a display signal. The computer display is controlled in response to the display signal. In an embodiment of the invention, an electromagnetic system includes at least one sensor producing EM waves and one receiving EM waves. A reflecting antenna is operatively connected to the input system for interacting with the electromagnetic waves and producing relative distance traveled information. Algorithms convert the relative distance traveled information to display signals. A system controls the computer display according to said display signals.
Other features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description and by practice of the invention.